Thin-film silicon materials and their alloys underpin a diverse range of electronic systems, from active matrix flat-panel displays, through solar panels for the ‘green-power’ generation, to surface micromanaged MEMS devices. Thin-film silicon can possess a diverse range of structures, from being fully amorphous to fully polycrystalline, as well as allowing mixed-phase states, such as micro- and nanocrystalline silicon. Such diversity has made large-area electronics one of the fastest growing semiconductor technologies, although not without introducing some complexity. This book addresses issues related to both fundamental materials science and applied technology and offers an overview of studies on film growth and crystallization, materials characterization, defects, metastability and carrier transport, as well as devices such as solar cells and thin-film transistors. The importance of developing efficient solar cells is reflected in the number of reports that seek to improve lifetime and efficiency, as well as light trapping, in solar cells.